Many common hair curling products involve the use of heat or chemicals or multiple pieces with clips and pins involved, so that their use takes a lot of time and is limited. Most hair curlers involve multiple, individual pieces that are secured in the hair with clips or pins and are uncomfortable to wear yet still require heat to curl. Conventional hair styling devices such as cloth covered elastic bands can be used to retain hair in a braid or a ponytail or to hold hair away from a user's face, but such devices are fashion devices for styling hair and provide limited curling ability, and the inevitable pull on a hair bundle can be irritating to the wearer. Metallic or plastic clips can also retain hair, but are not used for curling the hair. Some representative approaches are disclosed in Ripley, U.S. Pat. No. 5,499,638, Harvie, U.S. Pat. No. 8,757,176, Beadle, U.S. Pat. No. 1,916,943, Scheanblum et al., U.S. Pat. No. 1,512,490, and Pilan, U.S. Patent Application Publication 2013/0042885, all of which are incorporated herein by reference. In one example disclosed in Bailey, U.S. Pat. No. 6,397,854, a bendable fabric-covered rod-like device is described for use as a hair holder such as for a ponytail or a headband. However, while such a device can be used as a hair curling rod, its primary purpose is a fashion accessory to decorate the hair. Its applicability to hair curling is limited because while Bailey's aluminum flexible center will hold a ponytail, or secure the hair away from the face, it is not designed to hold the weight of all of the hair rolled around the device on the head for long enough to supply significant curling without additional clips and will not securely hold hair while sleeping overnight. Devices specifically designed for putting in the hair to curl it and then removing from the hair to produce the desired style of curls and waves that are quick, simple, inexpensive, and comfortable remain needed.